Cultivating anger is ultimately self-destructive. It’s also a choice, not a necessity.
Philosopher Martha Nussbaum’s book, Anger and Forgiveness: Resentment, Generosity, Justice, which I’ve recently read, provides a liberating framework for thinking about this topic. I’m sure I’m going to need to read it again. She thinks that anger has a very limited role to play in creating social good, and her critique of modern ideas about forgiveness is brilliant. Her analysis of the ways that Ghandi, Martin Luther King, and Nelson Mandela approached these questions is worth the read all by themselves.